Risk factors for recurrence of chronic subdural hematoma after surgical evacuation: a systematic review and meta-analysis.

Chronic subdural hematoma (CSDH) is a common neurosurgical condition. Surgical evacuation has remained the primary treatment despite many advancements in the endovascular field. Regardless, recurrence requiring reoperation is commonly observed during the postoperative follow-up. Herein, we aimed to investigate risk factors for recurrence after surgical evacuation. A review of MEDLINE, EMBASE, Web of Science, and Scopus was conducted using the designed search string. Studies were reviewed based on the predefined eligibility criteria. Data regarding sixty potential risk factors along with operational information were extracted for analysis. A meta-analysis using the random-effect model was conducted, and each risk factor affecting the postoperative recurrence of CSDH was then evaluated and graded. A total of 198 records met the eligibility criteria. A total number of 8523 patients with recurrent CSDH and 56,096 with non-recurrent CSDH were included in the study. The recurrence rate after surgical evacuation was 12%. Fifteen preoperative, nine radiologic, four hematoma-related, and three operative and postoperative factors were associated with recurrence. Risk factors associated with recurrence after surgical evacuation are important in neurosurgical decision-making and treatment planning. Found risk factors in this study may be used as the basis for pre-operative risk assessment to choose patients who would benefit the most from surgical evacuation.

A Survey on Monitoring and Management of Cerebral Vasospasm and Delayed Cerebral Ischemia After Subarachnoid Hemorrhage: The Mantra Study.

INTRODUCTION: Cerebral infarction from delayed cerebral ischemia (DCI) is a leading cause of poor neurological outcome after aneurysmal subarachnoid hemorrhage (aSAH). We performed an international clinical practice survey to identify monitoring and management strategies for cerebral vasospasm associated with DCI in aSAH patients requiring intensive care unit admission. METHODS: The survey questionnaire was available on the European Society of Intensive Care Medicine (May 2021-June 2022) and Neurocritical Care Society (April - June 2022) websites following endorsement by these societies. RESULTS: There were 292 respondents from 240 centers in 38 countries. In conscious aSAH patients or those able to tolerate an interruption of sedation, neurological examination was the most frequently used diagnostic modality to detect delayed neurological deficits related to DCI caused by cerebral vasospasm (278 respondents, 95.2%), while in unconscious patients transcranial Doppler/cerebral ultrasound was most frequently used modality (200, 68.5%). Computed tomography angiography was mostly used to confirm the presence of vasospasm as a cause of DCI. Nimodipine was administered for DCI prophylaxis by the majority of the respondents (257, 88%), mostly by an enteral route (206, 71.3%). If there was a significant reduction in arterial blood pressure after nimodipine administration, a vasopressor was added and nimodipine dosage unchanged (131, 45.6%) or reduced (122, 42.5%). Induced hypertension was used by 244 (85%) respondents as first-line management of DCI related to vasospasm; 168 (59.6%) respondents used an intra-arterial procedure as second-line therapy. CONCLUSIONS: This survey demonstrated variability in monitoring and management strategies for DCI related to vasospasm after aSAH. These findings may be helpful in promoting educational programs and future research.

Risk Factors for Delayed Cerebral Ischemia in Good-Grade Patients With Aneurysmal Subarachnoid Hemorrhage.

Background A subset of good-grade patients with aneurysmal subarachnoid hemorrhage (aSAH) develop delayed cerebral ischemia (DCI) that may cause permanent disabilities after aSAH. However, little is known about the risk factors of DCI among this specific patient group. Methods and Results We obtained a multinational cohort of good-grade (Glasgow Coma Scale 13-15 on admission) patients with aSAH by pooling patient data from 4 clinical trials and 2 prospective cohort studies. We collected baseline data on lifestyle-related factors and the clinical characteristics of aSAHs. By calculating fully adjusted risk estimates for DCI and DCI-related poor outcome, we identified the most high-risk patient groups. The pooled study cohort included 1918 good-grade patients with aSAH (median age, 51 years; 64% women), of whom 21% and 7% experienced DCI and DCI-related poor outcome, respectively. Among men, patients with obesity and (body mass index ≥30 kg/m2) thick aSAH experienced most commonly DCI (33%) and DCI-related poor outcome (20%), whereas none of the normotensive or young (aged <50 years) men with low body mass index (body mass index <22.5 kg/m2) had DCI-related poor outcome. In women, the highest prevalence of DCI (28%) and DCI-related poor outcome (13%) was found in patients with preadmission hypertension and thick aSAH. Conversely, the lowest rates (11% and 2%, respectively) were observed in normotensive women with a thin aSAH. Conclusions Increasing age, thick aSAH, obesity, and preadmission hypertension are risk factors for DCI in good-grade patients with aSAH. These findings may help clinicians to consider which good-grade patients with aSAH should be monitored carefully in the intensive care unit.

Management of Intracranial Hemorrhage in the Anticoagulated Patient.

Antiplatelet and anticoagulant drugs (antithrombotic drugs) can cause or be associated with intracranial hemorrhage. Patients who take antithrombotic drugs are at higher risk for intracranial hemorrhage after trauma and are neurologically worse acutely compared with patients not on antithrombotic drugs. Treatment of patients on antithrombotic drugs who have intracranial hemorrhage includes reversal of anticoagulant drugs in almost all cases. This article is a synopsis of the data pertaining to intracranial hemorrhage and antithrombotic drugs and methods to diagnose the pharmacologic effects and to reverse the effects of these drugs in patients with traumatic or spontaneous intracranial hemorrhage.

Bilirubin and its oxidation products damage brain white matter.

Brain injury after intracerebral hemorrhage (ICH) occurs in cortex and white matter and may be mediated by blood breakdown products, including hemoglobin and heme. Effects of blood breakdown products, bilirubin and bilirubin oxidation products, have not been widely investigated in adult brain. Here, we first determined the effect of bilirubin and its oxidation products on the structure and function of white matter in vitro using brain slices. Subsequently, we determined whether these compounds have an effect on the structure and function of white matter in vivo. In all, 0.5 mmol/L bilirubin treatment significantly damaged both the function and the structure of myelinated axons but not the unmyelinated axons in brain slices. Toxicity of bilirubin in vitro was prevented by dimethyl sulfoxide. Bilirubin oxidation products (BOXes) may be responsible for the toxicity of bilirubin. In in vivo experiments, unmyelinated axons were found more susceptible to damage from bilirubin injection. These results suggest that unmyelinated axons may have a major role in white-matter damage in vivo. Since bilirubin and BOXes appear in a delayed manner after ICH, preventing their toxic effects may be worth investigating therapeutically. Dimethyl sulfoxide or its structurally related derivatives may have a potential therapeutic value at antagonizing axonal damage after hemorrhagic stroke.

Intracranial drug delivery for subarachnoid hemorrhage.

Tice and colleagues pioneered site-specific, sustained-release drug delivery to the brain almost 30 years ago. Currently there is one drug approved for use in this manner. Clinical trials in subarachnoid hemorrhage have led to approval of nimodipine for oral and intravenous use, but other drugs, such as clazosentan, hydroxymethylglutaryl CoA reductase inhibitors (statins) and magnesium, have not shown consistent clinical efficacy. We propose that intracranial delivery of drugs such as nimodipine, formulated in sustained-release preparations, are good candidates for improving outcome after subarachnoid hemorrhage because they can be administered to patients that are already undergoing surgery and who have a self-limited condition from which full recovery is possible.

Voltage-gated K+ channel dysfunction in myocytes from a dog model of subarachnoid hemorrhage.

Delayed cerebral vasospasm after subarachnoid hemorrhage is primarily due to sustained contraction of arterial smooth muscle cells. Its pathogenesis remains unclear. The degree of arterial constriction is regulated by membrane potential that in turn is determined predominately by K+ conductance (GK). Here, we identified the main voltage-gated K+ (Kv) channels contributing to outward delayed rectifier currents in dog basilar artery smooth muscle as Kv2 class through a combination of electrophysiological and pharmacological methods. Kv2 current density was nearly halved in vasospastic myocytes after subarachnoid hemorrhage (SAH) in dogs, and Kv2.1 and Kv2.2 were downregulated in vasospastic myocytes when examined by quantitative mRNA, Western blotting, and immunohistochemistry. Vasospastic myocytes were depolarized and had a smaller contribution of GK toward maintenance of their membrane potential. Pharmacological block of Kv current in control myocytes mimicked the depolarization observed in vasospastic arteries. The degree of membrane depolarization was found to be compatible with the amount of vasoconstriction observed after SAH. We conclude that Kv2 dysfunction after SAH contributes to the pathogenesis of delayed cerebral vasospasm. This may confer a novel target for treatment of delayed cerebral vasospasm.

Cerebral vasospasm: looking beyond vasoconstriction.

Cerebral vasospasm is an important syndrome that afflicts 30% of patients in the aftermath of, and secondary to, subarachnoid hemorrhage. Starting approximately one week after the hemorrhage, the condition worsens the prognosis of the hemorrhage significantly. Apart from general supportive care, no treatment exists for cerebral vasospasm. During the past 50 years, it was thought that the ischemia that signifies poor outcome is more or less exclusively caused by arterial narrowing. However, this idea has recently been challenged by the failure of the drug clazosentan to improve patient outcome, despite reversing vasoconstriction. In this article, we discuss the opinion that factors other than vasoconstriction are important in the pathophysiology and prognosis of cerebral vasospasm. Such factors include global ischemia, disruption of the blood-brain barrier, activation of apoptotic and inflammatory pathways, and cortical spreading depression.